Systems and methods for fast agc convergence using high-speed interface between baseband and rfic

ABSTRACT

With advanced compute capabilities and growing convergence of wireless standards, it is desirable to run multiple wireless standards, e.g., 4G, 5G NR, and Wi-Fi, on a single signal processing system. Automatic gain control (AGC) is a process of converging on a gain level for optimum signal reception considering the dynamic range of all the components in the receive chain, including analog and digital parts. For certain wireless standard such as Wi-Fi, AGC is required to complete within a short interval. Both RF and baseband gains have to be adjusted within this short time. Discloses in the present disclosure are embodiments of a high-speed and low pin-count interface between an RF circuit and a baseband circuit for AGC communication. The high-speed interface provides a light-weight serial protocol over one or more low-voltage differential signaling (LVDS) channels to meet a low-latency requirement for gain updates.

TECHNICAL FIELD

The present disclosure relates generally to systems and methods toimplement automatic gain control (AGC) for wireless signal processing.More particularly, the present disclosure relates to systems and methodsto implement automatic gain control for wireless signal processingacross base-band and radio frequency integrated circuit (RFIC).

BACKGROUND

The importance of wireless communication in today's society is wellunderstood by one of skill in the art. Advances in wireless technologieshave resulted in the ability of a communication system to supportwireless communications of different standards, e.g., 5G New Radio (NR),4G LTE, Wi-Fi, etc. Different wireless standards have aspects which arevery different from each other—fundamental frame structures, timing ofsymbols, forward error correction (FEC) codes.

With advanced compute capabilities and growing convergence of wirelessstandards, there is requirement to run multiple wireless standards,e.g., 4G LTE, 5G NR, and Wi-Fi, on a single hardware, e.g., a system ona chip (SoC). This requires simultaneously receiving and transmittingsignals corresponding to each radio standard and also process themaccording to the requirements of the corresponding radio standard.However, typical solutions involve providing separate hardware blocksspecific to each radio standard which in turn requires more area on theSoC and consumes more power. As the need for inter-operability amongdifferent types of wireless standards increases, improvements inresource flexibility and system configurability will become moreimportant.

Among various processes for signal processing, AGC is a process ofconverging on a gain level for optimum signal reception considering adynamic range of all components in a signal receiving chain (analog anddigital). For some wireless standard such as Wi-Fi, AGC is required tocomplete within a short interval, e.g., 2.4 μs. Both RF and base-bandgains have to be adjusted within this short interval. In certainsituations. Some RF analog components may be in a different IC from abaseband (BB) IC. Hence a high-speed interface may be needed between thedifferent ICs such that the AGC may be implemented within the requiredshort interval.

Accordingly, what is needed are systems, devices and methods thataddress the above-described issues.

BRIEF DESCRIPTION OF THE DRAWINGS

References will be made to embodiments of the disclosure, examples ofwhich may be illustrated in the accompanying figures. These figures areintended to be illustrative, not limiting. Although the accompanyingdisclosure is generally described in the context of these embodiments,it should be understood that it is not intended to limit the scope ofthe disclosure to these particular embodiments. Items in the figures maynot be to scale.

FIG. 1 depicts various open radio access network (RAN) deployments for atelecommunication service provider, according to embodiments of thepresent disclosure.

FIG. 2 depicts unified signal processing system with support for AGC andan RFIC interface on a signal reception path, according to embodimentsof the present disclosure.

FIG. 3 depicts a process of baseband-RFIC communication for AGCimplementation, according to embodiments of the present disclosure.

FIG. 4 graphically depicts a serial baseband-RFIC interface protocol,according to embodiments of the present disclosure.

FIG. 5 depicts a process of baseband-RFIC interface protocolimplementation, according to embodiments of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following description, for purposes of explanation, specificdetails are set forth in order to provide an understanding of thedisclosure. It will be apparent, however, to one skilled in the art thatthe disclosure can be practiced without these details. Furthermore, oneskilled in the art will recognize that embodiments of the presentdisclosure, described below, may be implemented in a variety of ways,such as a process, an apparatus, a system/device, or a method on atangible computer-readable medium.

Components, or modules, shown in diagrams are illustrative of exemplaryembodiments of the disclosure and are meant to avoid obscuring thedisclosure. It shall also be understood that throughout this discussionthat components may be described as separate functional units, which maycomprise sub-units, but those skilled in the art will recognize thatvarious components, or portions thereof, may be divided into separatecomponents or may be integrated together, including, for example, beingin a single system or component. It should be noted that functions oroperations discussed herein may be implemented as components. Componentsmay be implemented in software, hardware, or a combination thereof.

Furthermore, connections between components or systems within thefigures are not intended to be limited to direct connections. Rather,data between these components may be modified, re-formatted, orotherwise changed by intermediary components. Also, additional or fewerconnections may be used. It shall also be noted that the terms“coupled,” “connected,” “communicatively coupled,” “interfacing,”“interface,” or any of their derivatives shall be understood to includedirect connections, indirect connections through one or moreintermediary devices, and wireless connections. It shall also be notedthat any communication, such as a signal, response, reply,acknowledgement, message, query, etc., may comprise one or moreexchanges of information.

Reference in the specification to “one or more embodiments,” “preferredembodiment,” “an embodiment,” “embodiments,” or the like means that aparticular feature, structure, characteristic, or function described inconnection with the embodiment is included in at least one embodiment ofthe disclosure and may be in more than one embodiment. Also, theappearances of the above-noted phrases in various places in thespecification are not necessarily all referring to the same embodimentor embodiments.

The use of certain terms in various places in the specification is forillustration and should not be construed as limiting. The terms“include,” “including,” “comprise,” and “comprising” shall be understoodto be open terms and any examples are provided by way of illustrationand shall not be used to limit the scope of this disclosure.

A service, function, or resource is not limited to a single service,function, or resource; usage of these terms may refer to a grouping ofrelated services, functions, or resources, which may be distributed oraggregated. The use of memory, database, information base, data store,tables, hardware, cache, and the like may be used herein to refer tosystem component or components into which information may be entered orotherwise recorded. The terms “data,” “information,” along with similarterms, may be replaced by other terminologies referring to a group ofone or more bits, and may be used interchangeably. The terms “packet” or“frame” shall be understood to mean a group of one or more bits. Theterm “frame” or “packet” shall not be interpreted as limitingembodiments of the present invention to 5G networks. The terms “packet,”“frame,” “data,” or “data traffic” may be replaced by otherterminologies referring to a group of bits, such as “datagram” or“cell.” The words “optimal,” “optimize,” “optimization,” and the likerefer to an improvement of an outcome or a process and do not requirethat the specified outcome or process has achieved an “optimal” or peakstate.

It shall be noted that: (1) certain steps may optionally be performed;(2) steps may not be limited to the specific order set forth herein; (3)certain steps may be performed in different orders; and (4) certainsteps may be done concurrently.

A. Open RAN Deployment Models

A radio access network (RAN) is part of a telecommunication system. Itimplements a RAT to provide connection between a device, e.g., a mobilephone, and a core network (CN). Open RAN is an approach based oninteroperability and standardization of RAN elements including a unifiedinterconnection standard for white-box hardware and open source softwareelements from different vendors.

FIG. 1 depicts various open radio access network (RAN) deployments for atelecommunication service provider, according to embodiments of thepresent disclosure. As shown in FIG. 1 , a radio unit (RU) 102 maycouple to a virtual distribution unit (vDU) 112 with a split, e.g., ORAN7-2 split, which is a Low PHY/High PHY split for ultra-reliablelow-latency communication (URLLC) and near-edge deployment. The vDU 112then couples to a virtual central unit (vCU) 122 with a split, e.g.,split 2, which is referred as radio resource control and packet dataconvergence control split from the Layer 2 radio link control (RLC).Alternatively, a vDU may be deployed on the side of an RU 104, and thencouples to a vCU 124 with a split, e.g., split 2. Alternatively, adistribution unit (DU) and an RU may be integrated as an appliance 106,which then couples to a vCU 126 with a split, e.g., split 2.Alternatively, a RU may be a small cell RN (S-RU) 108 couples to a smallcell DU or vDU (S-vDU) 118 using a split, e.g., a MAC/PHY layer split(split 6). The S-vDU 118 then couple to a vCU 128 with a split, e.g.,split 2.

A service provider (SP) may adopt more than one Open RAN deploymentmodels based on band, fronthaul bandwidth requirements, or deploymenttype (macro/small cell), etc. Deployment models are influenced ordecided based on multiple factors, including Fibre availability,real-estate/site/location constraints at pre-aggregation (Pre-Agg) andcell sites, total cost of ownership (TCO), Operational preference, etc.It is desirable for SPs to achieve maximum consistency aroundarchitecture, systems and operational model across all these deploymentmodels.

With constant development of Wi-Fi technology, Wi-Fi access points(APs), especially 5G Wi-Fi APs, may transmit or receive signals at afrequency (e.g., 2.4 GHz, 5 GHz, or 6 GHz) within the frequency range 1(FR1) for 5G communication. An RU serving 5G communications may also beconfigured for transmitting or receiving 5G Wi-Fi signals. Accordingly,a 5G station or a 5G femtocell may be deployed to serve both 5G andWi-Fi communications. However, using specialized or separate hardware toseparately process the 5G and Wi-Fi standards would result in complexhardware, increase power consumption for operation, and drive up thecost of the of the whole system. It would be desirable to have a unifiedor at least partially unified hardware that may be configured forsimultaneous transmission and reception of different radio accesstechnologies, including Wi-Fi.

B. Embodiments for AGC Between Baseband and RFIC

FIG. 2 depicts unified signal processing system with support forautomatic gain control (AGC) and an RFIC interface on a signal receptionpath, according to embodiments of the present disclosure. The unifiedhardware comprises a baseband circuit 204 and a RFIC 202. The basebandcircuit 204 and the RFIC 202 may be integrated respectively as twoseparate chips. The RFIC 202 comprises at least a communicationinterface 210 for communication with the baseband circuit 204, one ormore registers 250, and an amplifier 260. A signal processing unit (SPU)240 is integrated within the baseband circuit. The SPU 240 comprises anRF controller 230, and an RF communication interface 220, whichcommunicates to the communication interface 210 via a communicationprotocol. The RF controller 230 may perform operations, e.g., gainwriting, to the RF communication interface 220 such that one or moregain settings may be transmitted to the RFIC 202 for gain updates. Inone or more embodiments, the between the RF communication interface 220and the communication interface 210 may be a low-voltage differentialsignaling (LVDS) interface, with the communication protocol as a serialprotocol that runs through one or more LVDS channels 270 to supporthigh-speed communication between the RF communication interface 220 andthe communication interface 210. Such a high-speed, low-overheadinterface may achieve a latency of under 100 ns per update.

The one or more registers 250 stores one or more measurements for the RFsignal received at the RFIC 202, e.g., received signal strengthindicator (RSSI) and one or more gain settings per antenna for one ormore frequency bands. The amplifier 260 performs signal amplificationusing the gain settings stored at one or more registers 250 to output anamplified signal 262, which is then converted by an analog-to digitalconverter (ADC) 242 into a digital signal 243. The communicationinterface 210 couples to the one or more registers 250 to read the RSSIvalues, which are transmitted to the RF communication interface 220, andwrite one or more gain settings, which are transmitted to the RFcommunication interface 220.

The digital signal 243 is processed by a digital down converter (DDC)unit 244, which comprises multiple DDCs with each DDC having respectivemixer and filter for independent operation. The digital signal 243 maybe disaggregated in the DDC unit 244 into different outputscorresponding to different RATs. Output from each DDC in the DDC unit244 are accumulatively fed (e.g., accumulated over a predeterminedinterval, such as 400 ns) into an automatic gain control (AGC) unit 248for gain control. The AGC unit 248 may also implement clear channelassessment (CCA) to determine if one or more RF bands are busy or not inuse. Parameters for gains applied to each DDC output may be read by theAGC unit 248 from the RF controller 230. On the other hand, outputs fromthe AGC unit 248 may be sent to the RF controller 230, and/or sent tothe RF programming interface 220 via direct hardware path for RSSI andgain programming. In one or more embodiments, the AGC unit may comprisea software-assisted hardware finite-state machine (FSM) to control theAGC process for gain updates.

In one or more embodiments, the AGC unit 248 in the baseband 204requires a continuous input of the signal levels (e.g., RSSI) in theRFIC 202 to estimate gain updates and send back the estimations to RFIC202 for implementation. In one or more embodiments, a high-speedinterface between baseband and RFIC is utilized to support high-speedbaseband-RFIC communication. The high-speed interface may use alight-weight serial protocol that runs at a predetermined frequency(e.g., 400 MHz) through one or more LVDS channels 270. Such an approachmay provide a custom protocol optimized for AGC. In contrast, a parallelsource synchronous bus for low-latency communication for AGC betweenbaseband-RFIC may involve 8-bit along with a clock signal. Although sucha parallel interface may run at lower speeds (e.g., around 50 MHz) whereskew and timing requirements may be met, the parallel interface need ahigher pin-count and strict timing budgets. Compared to the parallelinterface, the serial protocol disclosed in the present patent documentutilizes fewer pins and reduces the complexity of digital logic on theRFIC side. More details of the serial protocol and protocolimplementations are disclosed in FIGS. 4-5 and associated descriptions.

The baseband may be operated to support AGC control with a convergencerange, e.g., over 70 dB, in a short interval, e.g., less than 2.4 μs,for a fast path to RFIC for quick gain changes. The SPU may be operatedfor fast detection of Wi-Fi preamble to facilitate Wi-Fi receiving. Thetotal loop for an iteration of AGC may be achieved at 820 ns.

FIG. 3 depicts a process of baseband-RFIC communication for AGCimplementation, according to embodiments of the present disclosure. Instep 305, an RFIC receives a wireless signal across one or more wirelessstandard (or bands), e.g., 5G, LTE, or Wi-Fi, etc. In step 310, at leastone signal parameter, e.g., register gains and/or received signalstrength indicator (RSSI), corresponding to the one or more wirelessstandard (or bands), is transmitted to the baseband circuit via a serialinterface comprising a plurality of channels. In one or moreembodiments, the serial interface uses a serial protocol running at apredetermined frequency (e.g., 400 MHz) over an LVDS channel. In step315, the wireless signal is amplified, by an amplifier, based at leaston one or more gain settings, to output an amplified signal. In step320, the amplified signal is then converted, by an ADC in the basebandcircuit, into a digital signal. In step 325, the digital signal isprocessed, by a DDC unit comprising one or more DDCs, into one or moreDDC outputs with each DDC output corresponding to a wireless band. Instep 330, the one or more DDC outputs in the DDC unit are accumulativelyfed (accumulated over a predetermined interval and then fed) into an AGCunit to generate a gain signal comprising one or more gain updates. Instep 335, the gain signal is transmitted to the RFIC via the serialinterface. In step 340, the RFIC applied the one or more gain updates toupdate the one or more gain settings for desired gain controlimplementation.

C. Embodiments of Protocol for Interface Between Baseband and RFIC

In one or more embodiments, the AGC process is controlled by asoftware-assisted hardware FSM in a base-band circuit (e.g., anintegrated circuit or IC). The FSM may need at least two types ofmeasurements, including signal strength (e.g., RSSI) measurementperformed in the RFIC and energy measurement after analog-to-digitalconversion in the baseband.

FIG. 4 graphically depicts a serial baseband-RFIC interface protocol,according to embodiments of the present disclosure. Each signal (e.g.,the clock signal 410, the gain signal 420, the RSSI signals 432 and 434)shown in FIG. 4 may be a differential signal across a pair ofcomplementary signals. In one or more embodiments, the RSSI in thewireless signal may be sampled in the RFIC at a rate of approximately 20Msps (million samples per second) and produce multiple bits (e.g., 32bits) of data per sample. This translates to 640 Mbps data rate whichmay be achieved using two LVDS channels (for a RSSI signal with twodigits) operating at 400 MHz. Both LVDS channels may be sourcesynchronous to a clock signal 410 which is transmitted over a third LVDSchannel. The interface protocol for RSSI transmission, as shown in FIG.4 , comprises an in-band start bit 442 to denote start of transmission,a 4-bit operation code (op-code) 444 to determine type of a signalparameter or measurement data (e.g., RSSI) being sent, multiple bits ofmeasurement data 446 with the MSB starting first, and a parity bit 448.A receiver in a data transmission session aligns to the start bit 442during start of receiving. Some examples for the interface protocol forAGC are shown in Table 1 below.

Using an LVDS channel may be effective in shielding externalinterference without using a high voltage for signal transmissionbecause the “real” information relates to electrical difference betweenthe two signals, rather than the difference between a single wire andground. Since external interference tends to affect both wiresidentically, information for transmission is unaffected. Also, an LVDSchannel uses signals of equal and opposite polarity, interference fromthe signals in the LVDS channel for nearby circuits tend to cancel out.

TABLE 1 Exemplary interface protocol for AGC Data Op[2] Op[1:0] (Gain orRSSI) 0-BB 3’b00 {R × 1, R × 0} N = 16 bits 1-RF 3’b01 {R × 3, R × 2} N= 16 bits 3’b1× {R × 3, R × 2, R × 1, R × 0} N = 32 bits

FIG. 5 depicts a process of baseband-RFIC interface protocolimplementation, according to embodiments of the present disclosure. Instep 505, a wireless signal is sampled in the RFIC at a predeterminedsampling rate (e.g., 20 Msps) to generate measurement data for at leastone signal parameter (e.g., RSSI). In step 510, the measurement data aretransmitted to the baseband circuit via a serial interface (e.g., ahigh-speed serial interface) protocol using one or more channelsoperating at a predetermined frequency (e.g., 400 MHz). The one or morechannels may be LVDS channels, as shown in FIG. 4 . In step 515, thebaseband circuit performs serial-to-parallel conversion for themeasurement data and feeds the converted measurement data to the AGCunit. In step 520, the AGC unit (or AGC FSM) generates a gain signal 420comprising one or more gain updates based on at least the convertedmeasurement data. The gain signal may be 32-bit or 48-bit depending ontype of the value. In one or more embodiments, the one or more desiredgain settings are computed further based on energy measurement performedone the baseband circuit after an analog-to-digital conversion. In step525, the gain signal is transmitted to the RFIC via the serial interfaceusing a gain signal channel, which may also be an LVDS channel and alsosource synchronous running at 400 MHz. In step 530, the gain signal isreceived in the RFIC, converted to parallel and applied in the RFIC toimplement desired gain update for the wireless signal.

Latency of the gain update is critical to AGC implementation. A latencyof under 100 ns per update may be achieved using embodiments of thedisclosed high-speed, low-overhead interface. Although FIG. 4 shows aserial baseband-RFIC interface protocol using two RSSI channels 432 and434, one skilled in the art shall understand different numbers of RSSIchannels may also be applicable and embodiments of the disclosedbaseband-RFIC interface protocol may also be used for communication ofsignal measurements other than RSSI. Such variations shall be within thescope of the present patent disclosure.

Aspects of the present disclosure may be encoded upon one or morenon-transitory computer-readable media with instructions for one or moreprocessors or processing units to cause steps to be performed. It shallbe noted that the one or more non-transitory computer-readable mediashall include volatile and/or non-volatile memory. It shall be notedthat alternative implementations are possible, including a hardwareimplementation or a software/hardware implementation.Hardware-implemented functions may be realized using ASIC(s),programmable arrays, digital signal processing circuitry, or the like.Accordingly, the “means” terms in any claims are intended to cover bothsoftware and hardware implementations. Similarly, the term“computer-readable medium or media” as used herein includes softwareand/or hardware having a program of instructions embodied thereon, or acombination thereof. With these implementation alternatives in mind, itis to be understood that the figures and accompanying descriptionprovide the functional information one skilled in the art would requireto write program code (i.e., software) and/or to fabricate circuits(i.e., hardware) to perform the processing required.

It shall be noted that embodiments of the present disclosure may furtherrelate to computer products with a non-transitory, tangiblecomputer-readable medium that have computer code thereon for performingvarious computer-implemented operations. The media and computer code maybe those specially designed and constructed for the purposes of thepresent disclosure, or they may be of the kind known or available tothose having skill in the relevant arts. Examples of tangiblecomputer-readable media include, for example: magnetic media such ashard disks, floppy disks, and magnetic tape; optical media such asCD-ROMs and holographic devices; magneto-optical media; and hardwaredevices that are specially configured to store or to store and executeprogram code, such as application specific integrated circuits (ASICs),programmable logic devices (PLDs), flash memory devices, othernon-volatile memory (NVM) devices (such as 3D XPoint-based devices), andROM and RAM devices. Examples of computer code include machine code,such as produced by a compiler, and files containing higher level codethat are executed by a computer using an interpreter. Embodiments of thepresent disclosure may be implemented in whole or in part asmachine-executable instructions that may be in program modules that areexecuted by a processing device. Examples of program modules includelibraries, programs, routines, objects, components, and data structures.In distributed computing environments, program modules may be physicallylocated in settings that are local, remote, or both.

One skilled in the art will recognize no computing system or programminglanguage is critical to the practice of the present disclosure. Oneskilled in the art will also recognize that a number of the elementsdescribed above may be physically and/or functionally separated intomodules and/or sub-modules or combined together.

It will be appreciated to those skilled in the art that the precedingexamples and embodiments are exemplary and not limiting to the scope ofthe present disclosure. It is intended that all permutations,enhancements, equivalents, combinations, and improvements thereto thatare apparent to those skilled in the art upon a reading of thespecification and a study of the drawings are included within the truespirit and scope of the present disclosure. It shall also be noted thatelements of any claims may be arranged differently including havingmultiple dependencies, configurations, and combinations.

1. A method for implementing automatic gain control (AGC) comprising:receiving, at a radio-frequency integrated circuit (RFIC), a wirelesssignal across one or more wireless standards or bands; transmitting, viaa serial interface using a plurality of channels in the RFIC, at leastone signal parameter of the wireless signal to a baseband circuit;amplifying, using an amplifier in the RFIC, the wireless signal based onone or more gain settings to output an amplified signal; converting,using an analog-to-digital converter (ADC) in the baseband circuit, theamplified signal into a digital signal; processing, by a digital downconverter (DDC) unit comprising one or more DDCs, the digital signalinto one or more DDC outputs with each of the one or more DDC outputscorresponding to one of the one or more wireless standards or bands, theone or more DDC outputs are accumulatively fed into an AGC unit in thebaseband circuit; generating, using the AGC unit, a gain signalcomprising one or more gain updates based on the at least one signalparameter and the accumulatively fed DDC outputs; transmitting, via theserial interface, the gain signal to the RFIC; and applying, at theRFIC, one or more gain updates in the gain signal to update the one ormore gain settings for a desired gain control implementation.
 2. Themethod of claim 1, wherein the wireless signal is a Wi-Fi signal.
 3. Themethod of claim 1, wherein the at least one signal parameter comprises areceived signal strength indicator (RSSI).
 4. The method of claim 1,wherein the one or more channels comprise one or more low-voltagedifferential signaling (LVDS) channels.
 5. The method of claim 4,wherein the at least one signal parameter is transmitted using two LVDSchannels that are source synchronous to a clock signal, the clock signalis transmitted over a third LVDS channel.
 6. The method of claim 5,wherein the two LVDS channels use a serial protocol operating at apredetermined frequency.
 7. The method of claim 6, wherein the serialprotocol comprises an in-band start bit to denote start of transmission,a multi-bit operation code to determine type of measurement being sent,multiple bits of measurement data, and a parity bit.
 8. The method ofclaim 5, wherein the gain signal is transmitted via an LVDS channel thatis source synchronous to the clock signal.
 9. The method of claim 5,wherein the gain signal is different from the two LVDS channels fortransmitting the at least one signal parameter.
 10. A system forimplementing automatic gain control (AGC) comprising: a radio-frequencyintegrated circuit (RFIC) to receive a wireless signal across one ormore wireless standards or bands, the RFIC comprising: one or moreregisters to store at least one signal parameter for the wireless signaland one or more gain settings; an amplifier that amplifies the wirelesssignal based on the one or more gain settings to output an amplifiedsignal; and a communication interface coupled to the one or moreregisters, the communication interface reads the at least one signalparameter for transmitting; a baseband circuit coupled to the RFIC toreceive the amplified signal for signal processing, the baseband circuitcomprising: a radio-frequency (RF) communication interface coupled tothe communication interface in the RFIC via one or more serial channels,the RF communication interface receives the at least one signalparameter from the communication interface; an analog-to-digitalconverter (ADC) to convert the amplified signal into a digital signal; adigital down converter (DDC) unit comprising one or more DDCs to processthe digital signal into one or more DDC outputs; and an AGC unit coupledto the RF communication interface and the DDC unit, the AGC unitgenerates a gain signal comprising one or more gain updates based on theat least one signal parameter and the one or more DDC outputs, the gainsignal is transmitted from the RF communication interface to thecommunication interface in the RFIC to update the one or more gainsettings for a desired gain control implementation.
 11. The system ofclaim 10, wherein the wireless signal is a Wi-Fi signal.
 12. The systemof claim 10, wherein the at least one signal parameter comprises areceived signal strength indicator (RSSI).
 13. The system of claim 10,wherein the one or more channels comprises multiple low-voltagedifferential signaling (LVDS) channels.
 14. The system of claim 13,wherein the at least one signal parameter is transmitted using two LVDSchannels that are source synchronous to a clock signal, the clock signalis transmitted over a third LVDS channel.
 15. The system of claim 14,wherein the two LVDS channels use a serial protocol operating at apredetermined frequency.
 16. The system of claim 15, wherein the serialprotocol comprises an in-band start bit to denote start of transmission,a multi-bit operation code to determine type of a signal parameter beingsent, multiple bits of measurement data, and a parity bit.
 17. Thesystem of claim 14, wherein the gain signal is transmitted via an LVDSchannel that is different from the two LVDS channels for transmittingthe at least one signal parameter.
 18. A method for implementingautomatic gain control (AGC) comprising: transmitting, via one or morechannels through a communication interface, at least one signalparameter for a wireless signal from a radio-frequency integratedcircuit (RFIC) to a baseband circuit, the one or more channels arelow-voltage differential signaling (LVDS) channels that use a serialprotocol operating at a predetermined frequency; generating, using thebaseband circuit, a gain signal comprising one or more gain updatesbased on the at least one signal parameter; and transmitting, via achannel through the communication interface, the gain signal to the RFICfor gain update in the RFIC, the channel for gain signal transmission isan LVDS channel different from the one or more channels for transmittingthe at least one signal parameter.
 19. The method of claim 18, whereinthe one or more channels for transmitting the at least one signalparameter and the channel for the gain signal transmission are sourcesynchronous to a clock signal.
 20. The method of claim 18, wherein theserial protocol comprises an in-band start bit to denote start oftransmission, a multi-bit operation code to determine type of a signalparameter being sent, multiple bits of measurement data, and a paritybit.